1. Field of the Invention
This invention relates to photographic cameras adapted to be attachable to and detachable from motor drive units for selectively driving each of the film winding up and rewinding mechanisms, and more particularly to a motor driven camera having a provision for protecting the loaded film from fogging which might be otherwise encountered when the effective combination of the camera body and the motor drive unit therefor is established or broken.
2. Description of the Prior Art
A wide variaty of motor driven cameras have been developed including, for example, the one in which the camera body and the motor drive unit are formed in unison, and the one in which the effective combination of the camera body and the motor drive unit may be established or broken as desired. In the latter connection there are two types, one of which is to motor-drive only the film winding up mechanism while the rewinding mechanism is manually operated, and another type which is to selectively motor-drive each of the film winding and rewinding mechanisms.
Of these, the first named motor driven camera has many disadvantages from the standpoint of the camera systematization which enables the user to apply the camera in the optimum form with respect to the given photographic situation. This type of camera is also inconvenient in application to photography requiring manual operations based on the photographer's personal experience and insight. The second type of camera in which only the film winding up operation is performed by the motor drive unit, though having an advantage of enabling the user to couple the camera body and the motor easily and also to carry out either of the coupling and decoupling at a desired time with no probability of causing the loaded film to be fogged, is inconvenient when the necessity of a rapid rewinding operation is encountered.
The last mentioned or third type is most suited to the camera systematization from the points of view that either of the film having and rewinding operations can be selectively carried out by motor driving control and that the camera body and the motor drive unit may be coupled to, or decoupled from each other at a desired time. The conventional motor driven camera of this type has, however, a disadvantage that the coupling of the motor drive unit to the camera body requires somewhat time-consuming manipulation because a drive motion output shaft of the unit must be inserted through a hole provided in the bottom wall of the camera housing into a take-up spool of the film cartridge. Another disadvantage is that after the camera is loaded with a cartridge, it is impossible to decouple the unit from the camera body without causing the film to be fogged, as a light leak to the cartridge chamber occurs through the hole. If the user comes to desire a manual operation at a time during the motor driven operation, therefore, he must perform the manual operation while still permitting the camera to remain coupled with the motor drive unit. Thus, the design feature for the possibility of detaching the unit from the camera is lost. In this case, the user is also suffered from trouble about keeping the light-shielding cover for the hole for fear it is lost during the motor driven operation.
As the take-up spool of the film cartridge is driven for rotation while being supported between an upper shaft cooperating with a manually operable rewinding knob and a lower shaft, that is, the drive motion output shaft of the unit, an offset between the upper and lower shaft axes is liable to occur. If so, smooth rewinding operation is difficult to perform. After the rewinding operation is completed to take the cartridge out of the camera, the user needs to disengage not only the upper but the lower rewinding shaft from the spool of the cartridge. Such handling is somewhat troublesome and complex. Further, the provision for admitting the disengaging movement of the lower rewinding shaft must be made within the housing of the motor drive unit by means of a relatively large spare space. This is disadvantageous for the limitation of the size of the unit to a minimum.
An object of the present invention is to provide a motor driven camera system which has overcome the above mentioned conventional drawbacks.
Another object is to provide a camera adapted for use with a motor drive unit capable of selectively driving each of the film winding up and rewinding mechanisms of the camera and which enables the user to perform the attachment and detachment of the motor drive unit to and from the camera body by easy and simple manipulation at a desired time while still permitting the camera to be loaded with the film, as there is no possibility of causing the film to be fogged.
Still another object is to provide a camera of the character described capable of smooth automatic rewinding operation which is not affected by the accuracy of location of the drive motion output shaft of the unit attached to the camera.